#include<cstdio>
#include<iostream>

int main()
{
    printf("hello world\n");
    fputs("aaaa\n",stdout);
    fwrite("bbbb",1,4,stdout);
    fprintf(stdout,"ccc");

     //FILE* fp=fopen("log.txt","w"); //a:追加 
     //if(fp==nullptr)
     //{
     //   perror("fopen");
     //   return 1;
     //}

     //char buffer[1024];

     //const char* message = "hello world";
     //int i=0;
     //while(i<10)
     //{
     //   snprintf(buffer,sizeof(buffer),"%s:%d\n",message,i);
     //   fputs(buffer,fp);
     //   i++;
     //}

     //fclose(fp);
     //return 0;
}
